1. Field of the Invention
The present invention relates to a technology for controlling an image-data input/output process performed by an image forming apparatus connected to an image-data input unit such as a scanner and an image-data output unit such as a plotter.
2. Description of the Related Art
An image forming apparatus, which is connected to an image-data input unit such as a scanner and an image-data output unit such as a plotter, is configured to receive image data from the scanner and output the image data to the plotter. At this time, the image forming apparatus can perform a process of reading the image data received from the scanner (hereinafter, “a reading process”) in parallel with a process of outputting the image data to the plotter for printing out an image (hereinafter, “a printing process”). However, when a data size is large, the image forming apparatus may fail to perform the above processes in parallel. For example, in a case where a capacity of a page memory is insufficient, if most of the page memory is used for the printing process, the image forming apparatus may fail to perform the reading process in parallel with the printing process due to structural limits of a system. Consequently, a job productivity of the image forming apparatus is degraded.
To solve the problem, various image forming apparatuses have been developed. For example, an image forming apparatus disclosed in Japanese Patent Application Laid-open No. 2005-79646 is configured to assign a unique image identifier (ID) to each parameter indicating a request for an execution of an image-data input/output process. Therefore, an image-data input/output process to be executed next can be selected based on an image ID assigned to a parameter indicating a request for an execution of an image-data input/output process that is executed last.
A technology for using a common image format regardless of type of an image-data input/output device such as the scanner and the plotter has recently proposed. The common image format is generally represented by a red-green-blue (RGB) color space. However, RGB data requires a relatively large memory size, so that the RGB data is generally compressed into a joint photographic experts group (JPEG) format. However, as there are plural types of image data, sizes of compressed image data differ from one another depending on the types of the image data.
Furthermore, there has been developed an image forming apparatus to which a plurality of image-data input/output devices is connected, such as a printer, a facsimile, a World Wide Web (Web) application, an image storage medium (a secure digital (SD) card or the like), and a document box stored in a hard disk drive (HDD), in addition to the scanner and the plotter. If various combinations of the above image-data input/output devices are considered, the number of types of the image-data input/output devices becomes enormous. Moreover, there are various types of image forming apparatuses in all price ranges from low-end to high-end. Therefore, performances of the image forming apparatuses including a memory size are variously different from one another.
In this manner, when the image forming apparatus performs an image-data input/output process, wide range of conditions should be met for processing the image-data input/output process, such as a type of image data, a specification of an image-data input/output device where the image data is input/output, a state of the image forming apparatus, and the like. Under such circumstances, the method disclosed in Japanese Patent Application Laid-open No. 2005-79646 cannot be appropriately applied to a practical use. Therefore, there has been expected to achieve an image forming apparatus capable of optimally-dealing with the wide range of conditions for processing the image-data input/output process.